Methods for determining and displaying perfusion parameters in tomography, particularly in computed tomography, are widely known. In the process, conclusions about possible pathological changes of the tissue or an associated organ are drawn from the perfusion behavior of the tissue. To this end, the most diverse developments of the models used, such as the maximum slope model or the Patlak model, exist. Here, scan data is acquired at temporally short intervals, which have lengths which are as equal as possible, and data from the bolus application is also used directly where possible in order to determine perfusion parameters, such as the blood flow, the blood volume, start times, and means transit times, from model calculations using usually very noisy data.